I've been stalking your post, I love what you've done with the place. Cool pics of trips.
In town, short trips, stop and go. Get 8-10. On the highway unloaded I get 16-18. Towing the trailer an fully loaded with family and gear it gets 8-10. It does everything excellently, other than fuel econimy.. To replace it though with something that gets significantly better mpg would cost multi thousands of dollers.
I am not sure in the gear ratio, it is mostly bone stock.